Suspended ceiling system

ABSTRACT

A suspended ceiling system having a plurality of elongated ceiling panels each of which has a planar web section and rail portions extending along opposite side edges of the web section, a pair of channel-shaped wall mounts mounted on the opposed walls of a room, and having an upper laterally extending flange and a lower laterally extending flange on which one end of a ceiling panel rests. The ceiling panels are held in place by Z-shaped retainer clips which snap in between the upper and lower flanges of the wall supports at locations between the ceiling panel rails. Each clip has an upper horizontal leg extending inwardly and a lower horizontal leg extending outwardly. Each of the horizontal legs bear against a surface of a web section of a ceiling panel. The horizontal legs are connected by a diagonal leg which extends from the upper horizontal leg at the wall support to the lower horizontal leg away from the wall support. The diagonal leg clamps the horizontal legs against the upper and lower flanges of the wall support.

BACKGROUND OF THE INVENTION

This invention relates to suspended ceiling systems including a plurality of ceiling panels supported on wall mounted supports and optionally intermediate tee supports suspended from an overhead support. More particularly, this invention relates to suspended ceiling systems for use in correctional institutions and other applications requiring ceiling panels to have superior hold down resistance. This invention also relates to suspended ceiling systems for use in architectural ceiling systems, particularly in areas possibly subject to high wind uplift such as a tunnel.

Suspended ceiling systems typically include a plurality of rectangular metal ceiling panels including a planar web section, which is either solid or perforated, and side rails having a side wall extending upwardly from and along the length of the opposite edges of the web section. The opposite ends of the ceiling panels are supported on a flange of supports mounted on the opposite walls of a room. For larger rooms requiring ceiling panels end to end, one end or both ends of some ceiling panels are supported on the flanges of intermediate tee supports suspended from ceiling joist or similar overhead support. Primarily for security purposes, it is desirable for the ceiling support arrangement to be such that the ceiling panels cannot be removed, except for an access panel requiring special tools, and so that the ends of the ceiling panels cannot be pushed or pried away from supporting flanges of the wall-mounted supports or intermediate tee supports far enough for a prisoner to hide contraband, such as razor blades, drugs, or the like.

In one type prior security ceiling system, opposite ends of ceiling panels are fastened to both upper and lower flanges on wall-mounted supports and tee supports by tamper-proof metal screws. Installation of this type ceiling system is labor intensive and the heads of the screws for the lower flanges are visible and detract from the aesthetic appearance of the completed assembly. The fasteners also potentially provide an exposed avenue of attempted ceiling system breech.

In another type prior security ceiling system, wall mounts include a first angle fixture anchored into the wall on which the security panels rest and a second angle fixture anchored in the wall above the first angle and bearing against the top edges of the ceiling panel rails to restrain upward movement of the ceiling panels. The installation of this type security ceiling system also is labor intensive.

In still another type of prior security ceiling system, wall mounts and intermediate tee supports are extruded aluminum parts. The wall mounts are L-shaped and include a laterally extending support flange and guide-ways formed in the vertical part and the tee supports have a similar configuration. The ceiling panels are clamped against the support flanges of the wall mounts and tee support by extruded aluminum clamping members having a portion arranged to be received in the guide-ways. In addition to the cost associated with extruding the wall angles, tee supports and clamping members, the installation of this type system also can be labor intensive.

U.S. Pat. No. 5,263,295 seeks to overcome the problems explained above by the use of a “channel” or C-shaped retainer clip to hold the security panels in place within the flanges. While the C-shaped retainer clip does reduce the labor requirements for an installation, it has been found not to be sufficiently strong to completely prevent access to the ceiling area from strong individuals, or a strong external load such as a wind uplift. The present invention overcomes this weakness by producing a system which can withstand a force about more than 5 times that of the C-shaped retainer clip.

A primary object of this invention is to provide a suspended ceiling system including a mounting arrangement which is simply constructed, convenient to install, and substantially stronger than prior screw-less ceiling systems.

Another object of the invention is to provide such a ceiling system in which the mounting arrangement positively clamps substantially the entire width of the web section of the ceiling panels against support flanges on the wall supports and also the tee supports if used.

Another object is to provide an improved suspended ceiling systems for use in correctional institutions and other applications requiring tamper proof ceiling panels.

A further object is to provide an improved suspended ceiling system for use or use in architectural ceiling systems which may be subject to possible high wind uplift, e.g. tunnels.

These and other objects, aspects and advantages of the invention will become apparent to those skilled in the art upon reviewing the following detailed description, the drawings, and the appended claims.

SUMMARY OF THE INVENTION

The invention provides a suspended ceiling system for an enclosure, such as a prison, jail cell or tunnel, including a plurality of elongated ceiling panels having a planar web section and rail portions extending upwardly and longitudinally along each of the opposite side edges of the web section and a pair of generally channel-shaped wall supports adapted to be mounted on opposed walls of the enclosure. Each wall support has a vertical leg adapted to be mounted against a wall, an upper flange extending laterally inwardly from the upper portion of the vertical leg and a lower flange which extends laterally inwardly from a lower portion of the vertical leg and on which one end of the ceiling panels rests.

Generally inverted T-shaped intermediate supports are provided for enclosures requiring two or more ceiling panels end to end. The intermediate supports are supported from an overhead support and extend generally parallel to and spaced from an opposed pair of the wall supports. They include a vertical leg, first and second upper flanges extending laterally outwardly in opposite directions from an upper portion of the vertical leg and first and second upper flanges extending laterally outwardly in opposite directions from the lower portion of the vertical leg. A first group of a plurality of the ceiling panels, disposed side by side with respect to each other and with the rail portions of adjacent ceiling panels abutting, rest on the lower flanges of an intermediate support and a plurality of ceiling panels, disposed side by side with respect to each other and with the rail portions of adjacent panels abutting and disposed end to end with respect to the first group, rest on the other lower flange of an intermediate support.

The present invention is particularly directed to ceiling systems incorporating a Z-shaped retainer clip used to hold ceiling panels in place. The Z-shaped retainer clips snap in between the upper and lower flanges of the wall supports at locations between the ceiling panel rails. Each Z-shaped retainer clip has an upper horizontal leg and an lower horizontal leg each of which bear against a surface of the web sections of the ceiling panels and a diagonal leg which extends between the lower and upper horizontal legs and clamps those legs against the upper and lower flanges of the wall support. The upper horizontal leg extends laterally inwardly and the lower horizontal leg extends laterally outwardly so that the diagonal leg extends from the upper horizontal leg at about the wall support to about the end of the lower horizontal leg which is most distant from the wall support and clamps the horizontal legs against the upper and lower flanges of the wall support.

The Z-shaped retainer clip includes (I) a diagonal leg, (ii) a horizontal upper leg extending from the diagonal leg and adapted to fit against the underside of an upper flange of a wall support or an intermediate support (when used), (iii) a horizontal lower leg extending from the diagonal leg in a direction opposite to the direction of the horizontal upper leg and adapted to fit against the top surface of the web section of a ceiling panel resting on a lower flange of the wall support or intermediate support (when used), wherein the diagonal leg attaches to the horizontal upper leg at or about the wall support or intermediate support. The outside dimensions of the horizontal upper and lower legs of the Z-shaped retainer clip approximates the inside dimensions of the upper and lower flanges of the wall supports and intermediate supports, minus the thickness of the web section so that the Z-shaped retainer clips will fit and re-strain the web section from being pushed or pried up from the lower flanges.

The Z-shaped retainer clip has a height less than, but corresponding to at least a major portion of, the distance between the rail portions of each ceiling panel so that one clip restrains substantially the entire width of the web section.

The upper flanges of the wall supports and the intermediate supports preferably are narrower than the respective lower flanges and the upper horizontal leg of the Z-shaped retainer clips is generally narrower than the lower horizontal leg to facilitate installation of the Z-shaped retainer clips.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, perspective view (from above) of a suspended ceiling system incorporating various features of the invention.

FIG. 2 is a sectional view taken generally along 2-2 in FIG. 1.

FIG. 3 is an exploded, sectional and partially fragmentary view of a wall mount with a ceiling in place prior to installation of a retainer clip.

FIG. 4 is a sectional view taken generally along 4-4 in FIG. 1.

PRIOR ART FIGS. A-1, A-2, and A-3 are side views of, respectively, a flanged wall support, a prior art C-shaped retainer clip, and the prior art C-clip within the flanged ceiling wall support as evaluated in Comparative Example A.

FIGS. 5 a, 5 b and 5 c are side views of, respectively, a flanged wall support, a Z-shaped retainer clip of the present invention, and a Z-shaped retainer clip within a flanged ceiling wall support as evaluated in Example 1.

FIG. 6 is a side view of a Z-shaped retainer clip within a flanged ceiling wall support further including a metal shim.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a suspended ceiling system 10 for use in an enclosure or room, such as a prison or jail cell, or in a space subject to high wind uplift, such as a tunnel. The ceiling system 10 includes a plurality of rectangular ceiling panels 12, channel-spaced wall supports 14 (one shown) mounted on opposed walls 16 (one shown) and, when the dimensions of an area are such to require two or more ceiling panels end to end, a plurality of generally inverted T-shaped intermediate supports 18 extending parallel to an opposed pair of wall supports 16.

The ceiling panels 12, preferably brake formed, rolled or otherwise formed from a sheet metal such as steel, include an elongated planar web section 20, which can be solid or perforated, has an inner surface 22 facing the interior of the cell and an outer surface 24, and side rails 26 extending upwardly from and along the length of the opposite side edges of the web section 20. The ceiling panels 12 typically can be up to 15 feet and even longer when heavier sheet materials are used. For many applications a single ceiling panel 12 can span the width or length of a room or space and intermediate supports 18 are not required.

In the specific embodiment illustrated in FIG. 1, each of the side rails 26 has a vertically extending side wall 28 and an in-turned flange 30 extending laterally inwardly from the top portion of the side wall 28. If desired, the internal flanges 30 can be omitted.

The wall supports 14, preferably brake formed, rolled or otherwise formed from a sheet metal such as steel, include a vertical wall or leg 32, which are each mounted against a wall 16 by a plurality of bolts 34 anchored in the wall 16 or other suitable fastening means, an upper flange 36 extending laterally inwardly from the upper portion of the vertical leg 32 and a lower flange 38 extending laterally inward from the lower portion of the vertical leg 32. The wall mounts 14 typically are preferably approximately 10 feet long and are located on the walls 16 so that the lower flanges 36 are at the desired height of the ceiling. The upper and lower flanges 36 and 38 are spaced apart a sufficient distance for one end portion of a plurality of ceiling panels 10, disposed side by side with the side rails 26 of adjacent ceiling panels 10 abutting, to fit there between with the web sections 20 resting on the lower flange 36, as illustrated in FIG. 1.

The intermediate supports 18, preferably brake formed, rolled or otherwise made from a sheet metal such as steel, include a vertical leg 40, a pair of upper flanges 42 and 44 extending laterally in opposite directions from the upper portion of the vertical leg 40, and a pair of lower flanges 46 and 48 extending laterally in opposite directions from the lower portion of the vertical leg 40. The intermediate supports 18 are suspended from ceiling joists or other similar supports (not shown) by hangers or the like (not shown) and extend parallel to an opposed pair of wall supports 14. The intermediate supports 18 are spaced from each other and from a wall support 14 so that the distance between the vertical legs 40 of adjacent intermediate supports 18 and the distance between the vertical legs 32 of the wall supports 14 and the vertical legs of the intermediate supports 18 approximates, but is slightly greater than, the length of the ceiling panels 12.

The upper and lower flanges 42 and 46 extend from one side of the vertical leg 40 of each intermediate support 18 and are spaced apart a sufficient distance for one end portion of a first group X of the ceiling panels 12, disposed side by side with the side rails 26 of adjacent ceiling panels 12 abutting, to fit there between with the web sections 20 resting on the lower flange 46.

The upper and lower flanges 44 and 48 extend in the opposite direction (from flanges 42 and 46) from the vertical leg 40 and are spaced apart a sufficient distance for one end of a second group Y of ceiling panels 12, disposed side by side with respect to each other and end to end with respect to the first group X, to fit there between with the web sections resting on the lower flange 48 as illustrated in FIG. 1.

In the preferred construction illustrated, the intermediate supports 18 are similar to a pair of wall supports 14 which have been fastened together back to back by welding or the like, thereby reducing fabrication costs.

The ceiling panels 12 are held in place against the lower flanges 38 of the wall supports 14 by Z-shaped retainer clips 50 which have (I) a diagonal leg 52 extending diagonally between (ii) a horizontal inwardly extending upper leg 54 adapted to fit against the underside of the upper flange 36 of a wall support 14 and (iii) a horizontal outwardly extending lower leg 56 adapted to fit against the upper surface 24 of the web section 20 of a ceiling panel 12 as best illustrated in FIG. 2.

Referring to FIG. 3, the outside dimension A of the upper and lower legs 54 and 56 of the retainer clips 50 approximates the inside dimension B between the upper and lower flanges 36 and 38 of a wall support 14, minus the thickness of the web section 20 of the ceiling panels 12, so that there is a tight enough fit between the lower leg 56 of the retainer clip 50 and the web section 50 to prevent the ceiling panels 12 from being pushed or pried away from the lower flange 38 of the wall mount 14. Generally, the wall supports 14 and the intermediate supports 18 are formed from 12 gauge steel, the retainer clips 50 from 14 gauge steel. Thus dimension A is about 3.5 inches and dimension B is about 3.25 inches when the ceiling panels 12 are formed from 16 gauge steel.

While two or more Z-shaped retainer clips 50 can be used to hold each end of a ceiling panel 12 in place, they should have a total length corresponding to at least a majority of the width of the web section 20 of the ceiling panel 12. Preferably however, a single retainer clip is used at each end and each such clips is preferably at least 70%, and more preferably at least 80%, of the width of the web section being held in place. The use of a single retainer clip 50 to restrain substantially the entire width of a web section 20 provides improved resistance to the section being pushed or pried away from the lower flange 38 of the wall mounts 14. For example, when the inside width of the web section 20 is 12 inches, the retainer clips 50 can be about 9.5 inches long, and when the inside width is 18 inches, the retainer clips can be about 15.5 inches long.

As best shown in FIG. 4, the ceiling panels 12 are held against the lower flanges 46 and 48 of the intermediate supports 18 by retainer clips 50 a closely similar to or exactly like those described above. That is, they preferably are brake formed, rolled or otherwise formed from a sheet metal such as steel (e.g., 14 gauge steel), the inside dimension between the upper flanges 42 and 44 and the lower flanges 46 and 48 of the intermediate supports 18 is the same B for the wall supports 14 and the outside dimension of the upper and lower legs 58 and 60 of the retainer clips 50 a is the same A for the wall support retainer clips 50.

As best illustrated in FIGS. 2 and 3, the upper flange 56 of the wall support 14 preferably is somewhat narrower than the lower flange 38 and the upper leg 54 of the retainer clips 50 preferably also is narrower than the lower leg 56. This facilitates installation of the retainer clips 50 after the ceiling panels 12 have been laid in place. As a general guide, the width of the upper and lower flanges 36 and 38 of the wall supports 14 can be about 1-1.25 inches and about 1.75-2 inches, respectively, and the width of the upper and lower legs 54 and 56 of the Z-shaped retainer clips 50 can be about 0.875 inches and 1.5 inches, respectively. For overall aesthetic appearance, the lower flanges 46 and 48 of the intermediate supports 18 preferably are somewhat narrower than the lower flange 38 of the wall supports 14 so that the total width of the lower flanges 46 and 49 of the intermediate supports 18 is less than twice the width of a wall support flanges 38. Otherwise, the dimensional relationship of the flanges of the intermediate supports 18 and the retainer clips 50 a can be the same as discussed above.

The Z-shaped retaining clips provide substantially improved security over prior art C-shaped clips. For most applications, adequate protection is provided by use of the Z-shaped retainer clips 50 and 50 a alone. For other applications requiring more security, additional means for restraining the ceiling panels 12 from being pushed or pried away from the lower flanges of the wall supports and the intermediate supports can be provided.

As illustrated in FIG. 1, one or more conventional barbed, U-shaped metal fasteners 61 can be tapped on over the edges of the adjoining upper flange 36 of the wall supports 14 and the upper leg 54 of the retainer clips 50 to further secure the retainer clips 50 in place. Similar fasteners can be used with the upper flanges of the intermediate supports 18 and the retainer clips 50 a.

In the event some space exists between a ceiling panel web section 20 and the lower flange 38 of a wall support 14 or a lower flange 46, 48, of an intermediate support 18 after installation, e.g., because of a build up of manufacturing tolerances, thin metal shims 74 can be driven between the top surface 24 of the web section 20 and those lower flanges as illustrated in FIG. 6. As a further safety precaution, the side rails 26, of adjacent ceiling panels 12 can be fastened together with metal screws 76 or other suitable fasteners as illustrated in FIG. 1.

COMPARATIVE EXAMPLE A

The amount of force required for an individual to gain entry to the space above a conventional metal ceiling held in place within a wall support by a prior art C-shaped ceiling retainer clip was determined. A C-shaped retainer clip made of 14 gauge steel was evaluated. The horizontal upper leg extended 0.875 inches, the vertical leg was 3.25 inches high, and the horizontal lower leg extended 1.5 inches. The C-shaped retainer clip 100 and its placement within a wall support 14 above a metal ceiling panel 12 are shown schematically in PRIOR ART FIGS. A-1, A-2, and A-3.

The governing performance failure mode was bending of the bottom leg and the load required was 173 pounds.

EXAMPLE 1

The procedure of Comparative Example A was repeated with a 14-gauge steel Z-shaped retainer clip of the present invention. The clip 50 had the same overall dimensions as the C-shaped retainer clip, i.e. top leg 0.875″, bottom leg 1.5″, and height 3.25″. The diagonal leg was 3.57″ long. The Z-shaped retainer clip 50 and its placement within a wall support 14 above a ceiling panel 12 are shown schematically in FIGS. 5 a, 5 b, and 5 c.

The governing performance failure mode was buckling of the diagonal leg and the load required was 873 pounds.

From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the invention and, without departing from the spirit and scope thereof, make various changes and modifications to adapt it to various usages. 

1. A suspended ceiling system for an enclosure having opposed walls comprising: a plurality of elongated ceiling panels including a planar web section having opposed inner and outer surfaces respectively facing toward and away from the interior of the enclosure, opposed side edges, opposed end portions and a rail portion extending upwardly from and longitudinally along each of said side edges; a pair of generally channel-shaped wall supports adapted to be mounted on opposed walls of a room, each of said wall supports including a vertical leg adapted to be mounted against a wall, an upper flange extending laterally inwardly from an upper portion of said vertical leg and a lower flange extending laterally inwardly from a lower portion of said vertical leg, said upper and lower flanges being spaced apart a sufficient distance for one end portion of a plurality of said ceiling panels, disposed side by side with the rail portions of adjacent panels abutting, to fit there between and rest on said lower flange; and at least one Z-shaped retainer clip for each end of a ceiling panel, each of the retainer clips having (i) an upper leg extending laterally inwardly and adapted to fit against the underside of the upper flange of the wall support, (ii) a lower leg extending laterally outwardly and adapted to fit against the outer surface of the web section of said ceiling panel resting on the lower flange of said wall support, and (iii) a diagonal leg extending diagonally inwardly from the upper leg at about the wall support to the lower leg; the outside dimension of the upper and lower legs of said Z-shaped retainer clip approximating the inside dimension between upper and lower flanges of said wall support minus the thickness of the web section of said ceiling panel, whereby said Z-shaped retainer clip fits between the upper and lower flanges of the wall support with the upper leg bearing against the upper flange of said wall support member and the lower leg bearing against and clamping the web section against the lower flange of said wall support to retain said web section from being pushed or pried away such lower flange.
 2. The ceiling system of claim 1 wherein the Z-shaped retainer clip has a height less than, but corresponding to at least a major portion of, the distance between the rail portions on each ceiling panel so that one of said retainer clips restrains substantially the entire width of the web section.
 3. The ceiling system of claim 1 wherein the upper flange of the wall support and the upper leg of the retainer clip have a width substantially less than the width of the respective lower flange of the wall support and lower leg of the retainer clip so as to facilitate installation of the retainer clip.
 4. The ceiling system of claim 1 wherein each of said rail portions include a side wall extending upwardly from and longitudinally along the respective side edge portion of said web section; and an in-turned flange extending laterally inwardly from said side wall portion, whereby when a plurality of said ceiling panels are installed side by side, the side wall portions of adjacent ceiling panels abut.
 5. The ceiling system of claim 4 further including auxiliary retainer clips for installation at the joints between adjacent ceiling panels.
 6. The ceiling system of claim 1 further comprising at least one generally inverted T-shaped intermediate support member adapted to be supported from an overhead support and extending generally parallel to and spaced from an opposed pair of said wall supports, said intermediate support member including a vertical leg, first and second upper flanges extending laterally outwardly in opposite directions from an upper portion of said vertical leg and first and second lower flanges extending laterally outwardly in opposite directions from a lower portion of said vertical leg; the first upper and lower flanges of said intermediate support member being spaced apart a sufficient distance for one end portion of a first group of a plurality of said ceiling panels, disposed side by side with the rail portions of adjacent ceiling panels abutting, to fit between said first upper and lower flanges and rest on said first lower flange; the second upper and lower flanges of said intermediate support member being spaced apart a sufficient distance for one end of a second group of a plurality of said ceiling panels, disposed side by side with respect to each other and with the rail portions of adjacent panels abutting and disposed end to end with respect to the first group, to fit between said second upper and lower flanges and rest on said second lower flange; and a Z-shaped retainer clip for each of said ceiling panels adapted to fit between the first and second upper and lower flanges of said intermediate support member.
 7. The ceiling system of claim 6 wherein the Z-shaped retainer clip has a height less than, but corresponding to at least a major portion of, the distance between the rail portions for each ceiling panel so only one of said clips restrains substantially the entire width of said web section.
 8. The ceiling system of claim 7 wherein the first and second upper flanges of said intermediate support member and the upper leg of each Z-shaped retainer clip has a width substantially less than the width of the respective first and second lower flanges of said intermediate support member and said leg of each Z-shaped retainer clip.
 9. A building which comprises a suspended ceiling system for an enclosure having opposed walls comprising: a plurality of elongated ceiling panels including a planar web section having opposed inner and outer surfaces respectively facing toward and away from the interior of the enclosure, opposed side edges, opposed end portions and a rail portion extending upwardly from and longitudinally along each of said side edges; a pair of generally channel-shaped wall supports adapted to be mounted on opposed walls of a room, each of said wall supports including a vertical leg adapted to be mounted against a wall, an upper flange extending laterally inwardly from an upper portion of said vertical leg and a lower flange extending laterally inwardly from a lower portion of said vertical leg, said upper and lower flanges being spaced apart a sufficient distance for one end portion of a plurality of said ceiling panels, disposed side by side with the rail portions of adjacent panels abutting, to fit there between and rest on said lower flange; and at least one Z-shaped retainer clip for each end of a ceiling panel, each of the retainer clips having (i) an upper leg extending laterally inwardly and adapted to fit against the underside of the upper flange of the wall support, (ii) a lower leg extending laterally outwardly and adapted to fit against the outer surface of the web section of said ceiling panel resting on the lower flange of said wall support, and (iii) a diagonal leg extending diagonally inwardly from the upper leg at about the wall support to the lower leg; the outside dimension of the upper and lower legs of said Z-shaped retainer clip approximating the inside dimension between upper and lower flanges of said wall support minus the thickness of the web section of said ceiling panel, whereby said Z-shaped retainer clip fits between the upper and lower flanges of the wall support with the upper leg bearing against the upper flange of said wall support member and the lower leg bearing against and clamping the web section against the lower flange of said wall support to retain said web section from being pushed or pried away such lower flange.
 10. The building of claim 9 wherein the Z-shaped retainer clip has a height less than, but corresponding to at least a major portion of, the distance between the rail portions on each ceiling panel so that one of said retainer clips restrains substantially the entire width of the web section.
 11. The building of claim 9 wherein the upper flange of the wall support and the upper leg of the retainer clip have a width substantially less than the width of the respective lower flange of the wall support and lower leg of the retainer clip so as to facilitate installation of the retainer clip.
 12. The building of claim 9 wherein each of said rail portions include a side wall extending upwardly from and longitudinally along the respective side edge portion of said web section; and an in-turned flange extending laterally inwardly from said side wall portion, whereby when a plurality of said ceiling panels are installed side by side, the side wall portions of adjacent ceiling panels abut.
 13. The building of claim 12 further including auxiliary retainer clips for installation at the joints between adjacent ceiling panels.
 14. The building of claim 9 further comprising at least one generally inverted T-shaped intermediate support member adapted to be supported from an overhead support and extending generally parallel to and spaced from an opposed pair of said wall supports, said intermediate support member including a vertical leg, first and second upper flanges extending laterally outwardly in opposite directions from an upper portion of said vertical leg and first and second lower flanges extending laterally outwardly in opposite directions from a lower portion of said vertical leg; the first upper and lower flanges of said intermediate support member being spaced apart a sufficient distance for one end portion of a first group of a plurality of said ceiling panels, disposed side by side with the rail portions of adjacent ceiling panels abutting, to fit between said first upper and lower flanges and rest on said first lower flange; the second upper and lower flanges of said intermediate support member being spaced apart a sufficient distance for one end of a second group of a plurality of said ceiling panels, disposed side by side with respect to each other and with the rail portions of adjacent panels abutting and disposed end to end with respect to the first group, to fit between said second upper and lower flanges and rest on said second lower flange; and a Z-shaped retainer clip for each of said ceiling panels adapted to fit between the first and second upper and lower flanges of said intermediate support member.
 15. The building of claim 14 wherein the Z-shaped retainer clip has a height less than, but corresponding to at least a major portion of, the distance between the rail portions for each ceiling panel so only one of said clips restrains substantially the entire width of said web section.
 16. The building of claim 15 wherein the first and second upper flanges of said intermediate support member and the upper leg of each Z-shaped retainer clip has a width substantially less than the width of the respective first and second lower flanges of said intermediate support member and said leg of each Z-shaped retainer clip.
 17. The building of claim 9 wherein the suspended ceiling system is inside.
 18. The building of claim 9 wherein the suspended ceiling system is outside.
 19. The building of claim 18 wherein the building is a tunnel. 